備份 MBR
dd if=/dev/sda bs=512 count=1 of=mbr.img
HD Clone
dd if=/dev/sda of=/dev/bak-disk
HD Clone block size 加大 加速
dd if=/dev/sda of=/dev/bak-disk bs=16M status=progress
bs=blocksize
progress=狀態
HD Clean
dd if=/dev/zero of=/dev/delete-disk bs=16M status=progress